But when you use the BCC field, some email applications don't expose enough information in the email message to link it properly. If that's the case with your email system, you will need to use the CC line to ensure the headers are available.

You can mask the long Insightly mailbox address in the CC field with this trick:

Create a contact in your email address book for your Insightly mailbox address, such as "My Insightly Mailbox." You can then add the contact in the CC field when sending and mask the Insightly email address.